Cool research was published in Nature this past week. Nature is one of those classic scientific journals that researchers like to read. It has a wide audience because it not only spotlights medicine, but also geology, zoology, ecology. This research may give clues to the complexity on how we form words and speak.
A team of researchers at University of California San Francisco has uncovered the neurological basis of speech motor control, the complex coordinated activity of tiny brain regions that controls our lips, jaw, tongue and larynx as we speak. This has got to be a must-read for speech therapists!
The work has potential implications for developing computer-brain interfaces for artificial speech communication and for the treatment of speech disorders, like stuttering and even “slips of the tongue” – you know what I mean. It also sheds light on an ability that is unique to humans among living creatures but poorly understood.
Basically, they say that the brain’s higher order centers coordinate the actions of lower order centers like a conductor of an orchestra to create a symphony.
How did they do it?
They had epilepsy patients in brain surgery say certain common sounds in English (but these same sounds are found in many languages). Surgeons then mapped brain activity, and then researchers used a complex computer program to see patterns to the millisecond and as precise as to the millimeter.
Epilepsy surgery provides a unique place for research like this. They usually have surgery to remove parts of the brain that are triggers for the epileptic seizures. The brain has no pain receptors or neurons, and patients are usually awake for these operations. It is common for doctors to use a probe to see what happens or ask the patients to say or do something to minimize effects as they take out parts of the brain. (They don’t want to take something out that will prevent you to blink your eyes, for example, if they can help it).
I haven’t read the entire article, but overall they were able to see the pattern of messages from the “thought of speaking” to the coordination of lips, tongue, and larynx to produce sounds and words. For example, the team found that while the lips and tongue are each controlled by one set of neurons, the larynx is controlled by two.
- Osgood File Audio & Transcript: http://www.westwood-backup.com/pg/jsp/osgood/transcript.jsp?pid=35941
- Actual Article: http://www.readcube.com/articles/10.1038/nature11911